[ViewVC] Diff of: cvs/rxvt-unicode/src/perl/background

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.66 by root, Thu Jun 28 15:19:15 2012 UTC vs.
Revision 1.103 by root, Fri Nov 26 18:49:48 2021 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border	4	#:META:RESOURCE:%.border:boolean:respect the terminal border
5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates	5	#:META:RESOURCE:%.interval:seconds:minimum time between updates
		6	#:META:RESOURCE:pixmap:file[;geom]:set image as background
		7	#:META:RESOURCE:backgroundPixmap:file[;geom]:set image as background
		8	#:META:RESOURCE:tr:boolean:set root pixmap as background
		9	#:META:RESOURCE:transparent:boolean:set root pixmap as background
		10	#:META:RESOURCE:tint:color:tint background with color
		11	#:META:RESOURCE:tintColor:color:tint background with color
		12	#:META:RESOURCE:sh:number:shade background by number %
		13	#:META:RESOURCE:shading:number:shade background by number %
		14	#:META:RESOURCE:blr:HxV:gaussian-blur background with radii
		15	#:META:RESOURCE:blurRadius:HxV:gaussian-blur background with radii
		16	#:META:OSC:20:change/query background image
		17	#:META:OSC:705:change transparent background tint colour
6		18
7	=head1 NAME	19	=head1 NAME
8		20
9	background - manage terminal background	21	background - manage terminal background
10		22
11	=head1 SYNOPSIS	23	=head1 SYNOPSIS
12		24
13	urxvt --background-expr 'background expression'	25	urxvt --background-expr 'background expression'
14	--background-border	26	--background-border
15	--background-interval seconds	27	--background-interval seconds
16		28
		29	=head1 QUICK AND DIRTY CHEAT SHEET
		30
		31	Load a random jpeg image and tile the background with it without scaling
		32	or anything else:
		33
		34	load "/path/to/img.jpg"
		35
		36	The same, but use mirroring/reflection instead of tiling:
		37
		38	mirror load "/path/to/img.jpg"
		39
		40	Load an image and scale it to exactly fill the terminal window:
		41
		42	scale keep { load "/path/to/img.jpg" }
		43
		44	Implement pseudo-transparency by using a suitably-aligned root pixmap
		45	as window background:
		46
		47	rootalign root
		48
		49	Likewise, but keep a blurred copy:
		50
		51	rootalign keep { blur 10, root }
		52
17	=head1 DESCRIPTION	53	=head1 DESCRIPTION
18		54
19	This extension manages the terminal background by creating a picture that	55	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	56	is behind the text, replacing the normal background colour.
21		57
30		66
31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'	67	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		68
33	Or specified as a X resource:	69	Or specified as a X resource:
34		70
35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }	71	URxvt.background.expr: scale keep { load "/path/to/mybg.png" }
36		72
37	=head1 THEORY OF OPERATION	73	=head1 THEORY OF OPERATION
38		74
39	At startup, just before the window is mapped for the first time, the	75	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	76	expression is evaluated and must yield an image. The image is then
…		…
73	} else {	109	} else {
74	return load "$HOME/sunday.png";	110	return load "$HOME/sunday.png";
75	}	111	}
76	}	112	}
77		113
78	This expression is evaluated once per hour. It will set F<sunday.png> as	114	This inner expression is evaluated once per hour (and whenever the
		115	terminal window is resized). It sets F<sunday.png> as background on
79	background on Sundays, and F<weekday.png> on all other days.	116	Sundays, and F<weekday.png> on all other days.
80		117
81	Fortunately, we expect that most expressions will be much simpler, with	118	Fortunately, we expect that most expressions will be much simpler, with
82	little Perl knowledge needed.	119	little Perl knowledge needed.
83		120
84	Basically, you always start with a function that "generates" an image	121	Basically, you always start with a function that "generates" an image
…		…
107	get a percentage):	144	get a percentage):
108		145
109	scale 2, load "$HOME/mypic.png"	146	scale 2, load "$HOME/mypic.png"
110		147
111	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	148	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
112	has now two arguments, the C<200> and the C<load> expression, while	149	has now two arguments, the C<2> and the C<load> expression, while
113	C<load> only has one argument. Arguments are separated from each other by	150	C<load> only has one argument. Arguments are separated from each other by
114	commas.	151	commas.
115		152
116	Scale also accepts two arguments, which are then separate factors for both	153	Scale also accepts two arguments, which are then separate factors for both
117	horizontal and vertical dimensions. For example, this halves the image	154	horizontal and vertical dimensions. For example, this halves the image
118	width and doubles the image height:	155	width and doubles the image height:
119		156
120	scale 0.5, 2, load "$HOME/mypic.png"	157	scale 0.5, 2, load "$HOME/mypic.png"
121		158
122	IF you try out these expressions, you might suffer from sluggishness,	159	IF you try out these expressions, you might suffer from some sluggishness,
123	because each time the terminal is resized, it again loads the PNG image	160	because each time the terminal is resized, it loads the PNG image again
124	and scales it. Scaling is usually fast, but loading the image can be quite	161	and scales it. Scaling is usually fast (and unavoidable), but loading the
125	time consuming. This is where C<keep> comes in handy:	162	image can be quite time consuming. This is where C<keep> comes in handy:
126		163
127	scale 0.5, 2, keep { load "$HOME/mypic.png" }	164	scale 0.5, 2, keep { load "$HOME/mypic.png" }
128		165
129	The C<keep> operator executes all the statements inside the braces only	166	The C<keep> operator executes all the statements inside the braces only
130	once, or when it thinks the outcome might change. In other cases it	167	once, or when it thinks the outcome might change. In other cases it
…		…
155		192
156	This one first takes a snapshot of the screen background image, and then	193	This one first takes a snapshot of the screen background image, and then
157	moves it to the upper left corner of the screen (as opposed to the upper	194	moves it to the upper left corner of the screen (as opposed to the upper
158	left corner of the terminal window)- the result is pseudo-transparency:	195	left corner of the terminal window)- the result is pseudo-transparency:
159	the image seems to be static while the window is moved around.	196	the image seems to be static while the window is moved around.
		197
		198	=head2 COLOUR SPECIFICATIONS
		199
		200	Whenever an operator expects a "colour", then this can be specified in one
		201	of two ways: Either as string with an X11 colour specification, such as:
		202
		203	"red" # named colour
		204	"#f00" # simple rgb
		205	"[50]red" # red with 50% alpha
		206	"TekHVC:300/50/50" # anything goes
		207
		208	OR as an array reference with one, three or four components:
		209
		210	[0.5] # 50% gray, 100% alpha
		211	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		212	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
160		213
161	=head2 CACHING AND SENSITIVITY	214	=head2 CACHING AND SENSITIVITY
162		215
163	Since some operations (such as C<load> and C<blur>) can take a long time,	216	Since some operations (such as C<load> and C<blur>) can take a long time,
164	caching results can be very important for a smooth operation. Caching can	217	caching results can be very important for a smooth operation. Caching can
…		…
172	... }>. The C<keep> operator takes a block of multiple statements enclosed	225	... }>. The C<keep> operator takes a block of multiple statements enclosed
173	by C<{}> and keeps the return value in memory.	226	by C<{}> and keeps the return value in memory.
174		227
175	An expression can be "sensitive" to various external events, such as	228	An expression can be "sensitive" to various external events, such as
176	scaling or moving the window, root background changes and timers. Simply	229	scaling or moving the window, root background changes and timers. Simply
177	using an expression (such as C<scale> without parameters) that depend on	230	using an expression (such as C<scale> without parameters) that depends on
178	certain changing values (called "variables"), or using those variables	231	certain changing values (called "variables"), or using those variables
179	directly, will make an expression sensitive to these events - for example,	232	directly, will make an expression sensitive to these events - for example,
180	using C<scale> or C<TW> will make the expression sensitive to the terminal	233	using C<scale> or C<TW> will make the expression sensitive to the terminal
181	size, and thus to resizing events.	234	size, and thus to resizing events.
182		235
183	When such an event happens, C<keep> will automatically trigger a	236	When such an event happens, C<keep> will automatically trigger a
184	reevaluation of the whole expression with the new value of the expression.	237	reevaluation of the whole expression with the new value of the expression.
185		238
186	C<keep> is most useful for expensive operations, such as C<blur>:	239	C<keep> is most useful for expensive operations, such as C<blur>:
187		240
188	rootalign once { blur 20, root }	241	rootalign keep { blur 20, root }
189		242
190	This makes a blurred copy of the root background once, and on subsequent	243	This makes a blurred copy of the root background once, and on subsequent
191	calls, just root-aligns it. Since C<blur> is usually quite slow and	244	calls, just root-aligns it. Since C<blur> is usually quite slow and
192	C<rootalign> is quite fast, this trades extra memory (for the cached	245	C<rootalign> is quite fast, this trades extra memory (for the cached
193	blurred pixmap) with speed (blur only needs to be redone when root	246	blurred pixmap) with speed (blur only needs to be redone when root
…		…
208		261
209	=head1 REFERENCE	262	=head1 REFERENCE
210		263
211	=head2 COMMAND LINE SWITCHES	264	=head2 COMMAND LINE SWITCHES
212		265
213	=over 4	266	=over
214		267
215	=item --background-expr perl-expression	268	=item --background-expr perl-expression
216		269
217	Specifies the Perl expression to evaluate.	270	Specifies the Perl expression to evaluate.
218		271
…		…
238	=cut	291	=cut
239		292
240	our %_IMG_CACHE;	293	our %_IMG_CACHE;
241	our $HOME;	294	our $HOME;
242	our ($self, $frame);	295	our ($self, $frame);
243	our ($x, $y, $w, $h);	296	our ($x, $y, $w, $h, $focus);
244		297
245	# enforce at least this interval between updates	298	# enforce at least this interval between updates
246	our $MIN_INTERVAL = 6/59.951;	299	our $MIN_INTERVAL = 6/59.951;
247		300
248	{	301	{
…		…
259		312
260	These functions provide an image, by loading it from disk, grabbing it	313	These functions provide an image, by loading it from disk, grabbing it
261	from the root screen or by simply generating it. They are used as starting	314	from the root screen or by simply generating it. They are used as starting
262	points to get an image you can play with.	315	points to get an image you can play with.
263		316
264	=over 4	317	=over
265		318
266	=item load $path	319	=item load $path
267		320
268	Loads the image at the given C<$path>. The image is set to plane tiling	321	Loads the image at the given C<$path>. The image is set to plane tiling
269	mode.	322	mode.
270		323
271	If the image is already in memory (e.g. because another terminal instance	324	If the image is already in memory (e.g. because another terminal instance
272	uses it), then the in-memory copy us returned instead.	325	uses it), then the in-memory copy is returned instead.
273		326
274	=item load_uc $path	327	=item load_uc $path
275		328
276	Load uncached - same as load, but does not cache the image, which means it	329	Load uncached - same as load, but does not cache the image, which means it
277	is I<always> loaded from the filesystem again.	330	is I<always> loaded from the filesystem again, even if another copy of it
		331	is in memory at the time.
278		332
279	=cut	333	=cut
280		334
281	sub load_uc($) {	335	sub load_uc($) {
282	$self->new_img_from_file ($path)	336	$self->new_img_from_file ($_[0])
283	}	337	}
284		338
285	sub load($) {	339	sub load($) {
286	my ($path) = @_;	340	my ($path) = @_;
287		341
…		…
380	for @_;	434	for @_;
381		435
382	$base	436	$base
383	}	437	}
384		438
		439	=back
		440
385	=head2 TILING MODES	441	=head2 TILING MODES
386		442
387	The following operators modify the tiling mode of an image, that is, the	443	The following operators modify the tiling mode of an image, that is, the
388	way that pixels outside the image area are painted when the image is used.	444	way that pixels outside the image area are painted when the image is used.
389		445
390	=over 4	446	=over
391		447
392	=item tile $img	448	=item tile $img
393		449
394	Tiles the whole plane with the image and returns this new image - or in	450	Tiles the whole plane with the image and returns this new image - or in
395	other words, it returns a copy of the image in plane tiling mode.	451	other words, it returns a copy of the image in plane tiling mode.
…		…
470	dimensions. They are not (Perl-) variables, they just return stuff that	526	dimensions. They are not (Perl-) variables, they just return stuff that
471	varies. Most of them make your expression sensitive to some events, for	527	varies. Most of them make your expression sensitive to some events, for
472	example using C<TW> (terminal width) means your expression is evaluated	528	example using C<TW> (terminal width) means your expression is evaluated
473	again when the terminal is resized.	529	again when the terminal is resized.
474		530
475	=over 4	531	=over
476		532
477	=item TX	533	=item TX
478		534
479	=item TY	535	=item TY
480		536
481	Return the X and Y coordinates of the terminal window (the terminal	537	Return the X and Y coordinates of the terminal window (the terminal
482	window is the full window by default, and the character area only when in	538	window is the full window by default, and the character area only when in
483	border-respect mode).	539	border-respect mode).
484		540
485	Using these functions make your expression sensitive to window moves.	541	Using these functions makes your expression sensitive to window moves.
486		542
487	These functions are mainly useful to align images to the root window.	543	These functions are mainly useful to align images to the root window.
488		544
489	Example: load an image and align it so it looks as if anchored to the	545	Example: load an image and align it so it looks as if anchored to the
490	background (that's exactly what C<rootalign> does btw.):	546	background (that's exactly what C<rootalign> does btw.):
491		547
492	move -TX, -TY, keep { load "mybg.png" }	548	move -TX, -TY, keep { load "mybg.png" }
493		549
494	=item TW	550	=item TW
		551
		552	=item TH
495		553
496	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	554	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
497	terminal window is the full window by default, and the character area only	555	terminal window is the full window by default, and the character area only
498	when in border-respect mode).	556	when in border-respect mode).
499		557
500	Using these functions make your expression sensitive to window resizes.	558	Using these functions makes your expression sensitive to window resizes.
501		559
502	These functions are mainly useful to scale images, or to clip images to	560	These functions are mainly useful to scale images, or to clip images to
503	the window size to conserve memory.	561	the window size to conserve memory.
504		562
505	Example: take the screen background, clip it to the window size, blur it a	563	Example: take the screen background, clip it to the window size, blur it a
506	bit, align it to the window position and use it as background.	564	bit, align it to the window position and use it as background.
507		565
508	clip move -TX, -TY, keep { blur 5, root }	566	clip move -TX, -TY, keep { blur 5, root }
509		567
510	=cut	568	=item FOCUS
511		569
		570	Returns a boolean indicating whether the terminal window has keyboard
		571	focus, in which case it returns true.
		572
		573	Using this function makes your expression sensitive to focus changes.
		574
		575	A common use case is to fade the background image when the terminal loses
		576	focus, often together with the C<-fade> command line option. In fact,
		577	there is a special function for just that use case: C<focus_fade>.
		578
		579	Example: use two entirely different background images, depending on
		580	whether the window has focus.
		581
		582	FOCUS ? keep { load "has_focus.jpg" } : keep { load "no_focus.jpg" }
		583
		584	=cut
		585
512	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }	586	sub TX () { $frame->[FR_AGAIN]{position} = 1; $x }
513	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }	587	sub TY () { $frame->[FR_AGAIN]{position} = 1; $y }
514	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }	588	sub TW () { $frame->[FR_AGAIN]{size} = 1; $w }
515	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }	589	sub TH () { $frame->[FR_AGAIN]{size} = 1; $h }
		590	sub FOCUS() { $frame->[FR_AGAIN]{focus} = 1; $focus }
516		591
517	=item now	592	=item now
518		593
519	Returns the current time as (fractional) seconds since the epoch.	594	Returns the current time as (fractional) seconds since the epoch.
520		595
…		…
554		629
555	=head2 SHAPE CHANGING OPERATORS	630	=head2 SHAPE CHANGING OPERATORS
556		631
557	The following operators modify the shape, size or position of the image.	632	The following operators modify the shape, size or position of the image.
558		633
559	=over 4	634	=over
560		635
561	=item clip $img	636	=item clip $img
562		637
563	=item clip $width, $height, $img	638	=item clip $width, $height, $img
564		639
…		…
567	Clips an image to the given rectangle. If the rectangle is outside the	642	Clips an image to the given rectangle. If the rectangle is outside the
568	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is	643	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is
569	larger than the image, then the tiling mode defines how the extra pixels	644	larger than the image, then the tiling mode defines how the extra pixels
570	will be filled.	645	will be filled.
571		646
572	If C<$x> an C<$y> are missing, then C<0> is assumed for both.	647	If C<$x> and C<$y> are missing, then C<0> is assumed for both.
573		648
574	If C<$width> and C<$height> are missing, then the window size will be	649	If C<$width> and C<$height> are missing, then the window size will be
575	assumed.	650	assumed.
576		651
577	Example: load an image, blur it, and clip it to the window size to save	652	Example: load an image, blur it, and clip it to the window size to save
…		…
595	=item scale $width_factor, $height_factor, $img	670	=item scale $width_factor, $height_factor, $img
596		671
597	Scales the image by the given factors in horizontal	672	Scales the image by the given factors in horizontal
598	(C<$width>) and vertical (C<$height>) direction.	673	(C<$width>) and vertical (C<$height>) direction.
599		674
600	If only one factor is give, it is used for both directions.	675	If only one factor is given, it is used for both directions.
601		676
602	If no factors are given, scales the image to the window size without	677	If no factors are given, scales the image to the window size without
603	keeping aspect.	678	keeping aspect.
604		679
605	=item resize $width, $height, $img	680	=item resize $width, $height, $img
…		…
730	=item rotate $center_x, $center_y, $degrees, $img	805	=item rotate $center_x, $center_y, $degrees, $img
731		806
732	Rotates the image clockwise by C<$degrees> degrees, around the point at	807	Rotates the image clockwise by C<$degrees> degrees, around the point at
733	C<$center_x> and C<$center_y> (specified as factor of image width/height).	808	C<$center_x> and C<$center_y> (specified as factor of image width/height).
734		809
735	Example: rotate the image by 90 degrees around it's center.	810	Example: rotate the image by 90 degrees around its center.
736		811
737	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }	812	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
738		813
739	=cut	814	=cut
740		815
…		…
751		826
752	=head2 COLOUR MODIFICATIONS	827	=head2 COLOUR MODIFICATIONS
753		828
754	The following operators change the pixels of the image.	829	The following operators change the pixels of the image.
755		830
756	=over 4	831	=over
		832
		833	=item tint $color, $img
		834
		835	Tints the image in the given colour.
		836
		837	Example: tint the image red.
		838
		839	tint "red", load "rgb.png"
		840
		841	Example: the same, but specify the colour by component.
		842
		843	tint [1, 0, 0], load "rgb.png"
		844
		845	=cut
		846
		847	sub tint($$) {
		848	$_[1]->tint ($_[0])
		849	}
		850
		851	=item shade $factor, $img
		852
		853	Shade the image by the given factor.
		854
		855	=cut
		856
		857	sub shade($$) {
		858	$_[1]->shade ($_[0])
		859	}
757		860
758	=item contrast $factor, $img	861	=item contrast $factor, $img
759		862
760	=item contrast $r, $g, $b, $img	863	=item contrast $r, $g, $b, $img
761		864
…		…
791	latter in a white picture.	894	latter in a white picture.
792		895
793	Due to idiosyncrasies in the underlying XRender extension, biases less	896	Due to idiosyncrasies in the underlying XRender extension, biases less
794	than zero can be I<very> slow.	897	than zero can be I<very> slow.
795		898
		899	You can also try the experimental(!) C<muladd> operator.
		900
796	=cut	901	=cut
797		902
798	sub contrast($$;$$;$) {	903	sub contrast($$;$$;$) {
799	my $img = pop;	904	my $img = pop;
800	my ($r, $g, $b, $a) = @_;	905	my ($r, $g, $b, $a) = @_;
…		…
815	$a = 1 if @_ < 4;	920	$a = 1 if @_ < 4;
816		921
817	$img = $img->clone;	922	$img = $img->clone;
818	$img->brightness ($r, $g, $b, $a);	923	$img->brightness ($r, $g, $b, $a);
819	$img	924	$img
		925	}
		926
		927	=item muladd $mul, $add, $img # EXPERIMENTAL
		928
		929	First multiplies the pixels by C<$mul>, then adds C<$add>. This can be used
		930	to implement brightness and contrast at the same time, with a wider value
		931	range than contrast and brightness operators.
		932
		933	Due to numerous bugs in XRender implementations, it can also introduce a
		934	number of visual artifacts.
		935
		936	Example: increase contrast by a factor of C<$c> without changing image
		937	brightness too much.
		938
		939	muladd $c, (1 - $c) * 0.5, $img
		940
		941	=cut
		942
		943	sub muladd($$$) {
		944	$_[2]->muladd ($_[0], $_[1])
820	}	945	}
821		946
822	=item blur $radius, $img	947	=item blur $radius, $img
823		948
824	=item blur $radius_horz, $radius_vert, $img	949	=item blur $radius_horz, $radius_vert, $img
…		…
836	sub blur($$;$) {	961	sub blur($$;$) {
837	my $img = pop;	962	my $img = pop;
838	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	963	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
839	}	964	}
840		965
		966	=item focus_fade $img
		967
		968	=item focus_fade $factor, $img
		969
		970	=item focus_fade $factor, $color, $img
		971
		972	Fades the image by the given factor (and colour) when focus is lost (the
		973	same as the C<-fade>/C<-fadecolor> command line options, which also supply
		974	the default values for C<factor> and C<$color>. Unlike with C<-fade>, the
		975	C<$factor> is a real value, not a percentage value (that is, 0..1, not
		976	0..100).
		977
		978	Example: do the right thing when focus fading is requested.
		979
		980	focus_fade load "mybg.jpg";
		981
		982	=cut
		983
		984	sub focus_fade($;$$) {
		985	my $img = pop;
		986
		987	return $img
		988	if FOCUS;
		989
		990	my $fade = @_ >= 1 ? $_[0] : defined $self->resource ("fade") ? $self->resource ("fade") * 0.01 : 0;
		991	my $color = @_ >= 2 ? $_[1] : $self->resource ("color+" . urxvt::Color_fade);
		992
		993	$img = $img->tint ($color) if $color ne "rgb:00/00/00";
		994	$img = $img->muladd (1 - $fade, 0) if $fade;
		995
		996	$img
		997	}
		998
841	=back	999	=back
842		1000
843	=head2 OTHER STUFF	1001	=head2 OTHER STUFF
844		1002
845	Anything that didn't fit any of the other categories, even after applying	1003	Anything that didn't fit any of the other categories, even after applying
846	force and closing our eyes.	1004	force and closing our eyes.
847		1005
848	=over 4	1006	=over
849		1007
850	=item keep { ... }	1008	=item keep { ... }
851
852	#TODO#
853		1009
854	This operator takes a code block as argument, that is, one or more	1010	This operator takes a code block as argument, that is, one or more
855	statements enclosed by braces.	1011	statements enclosed by braces.
856		1012
857	The trick is that this code block is only evaluated once - future calls	1013	The trick is that this code block is only evaluated when the outcome
858	will simply return the original image (yes, it should only be used with	1014	changes - on other calls the C<keep> simply returns the image it computed
859	images).	1015	previously (yes, it should only be used with images). Or in other words,
		1016	C<keep> I<caches> the result of the code block so it doesn't need to be
		1017	computed again.
860		1018
861	This can be extremely useful to avoid redoing the same slow operations	1019	This can be extremely useful to avoid redoing slow operations - for
862	again and again- for example, if your background expression takes the root	1020	example, if your background expression takes the root background, blurs it
863	background, blurs it and then root-aligns it it would have to blur the	1021	and then root-aligns it it would have to blur the root background on every
864	root background on every window move or resize.	1022	window move or resize.
		1023
		1024	Another example is C<load>, which can be quite slow.
865		1025
866	In fact, urxvt itself encloses the whole expression in some kind of	1026	In fact, urxvt itself encloses the whole expression in some kind of
867	C<once> block so it only is reevaluated as required.	1027	C<keep> block so it only is reevaluated as required.
868		1028
869	Putting the blur into a C<once> block will make sure the blur is only done	1029	Putting the blur into a C<keep> block will make sure the blur is only done
870	once:	1030	once, while the C<rootalign> is still done each time the window moves.
871		1031
872	rootlign keep { blur 10, root }	1032	rootalign keep { blur 10, root }
873		1033
874	This leaves the question of how to force reevaluation of the block,	1034	This leaves the question of how to force reevaluation of the block,
875	in case the root background changes: If expression inside the block	1035	in case the root background changes: If expression inside the block
876	is sensitive to some event (root background changes, window geometry	1036	is sensitive to some event (root background changes, window geometry
877	changes), then it will be reevaluated automatically as needed.	1037	changes), then it will be reevaluated automatically as needed.
878		1038
879	=item once_again	1039	=back
880		1040
881	Resets all C<once> block as if they had never been called, i.e. on the	1041	=head1 OLD BACKGROUND IMAGE SETTINGS
882	next call they will be reevaluated again.
883		1042
884	=cut	1043	This extension also provides support for the old options/resources and
		1044	OSC sequences for setting a background image. These settings are
		1045	B<deprecated> and will be removed in future versions.
885		1046
		1047	=head2 OPTIONS AND RESOURCES
		1048
		1049	=over
		1050
		1051	=item B<-pixmap> I<file[;oplist]>
		1052
		1053	=item B<backgroundPixmap:> I<file[;oplist]>
		1054
		1055	Use the specified image file as the window's background and also
		1056	optionally specify a colon separated list of operations to modify it.
		1057	Note that you may need to quote the C<;> character when using the
		1058	command line option, as C<;> is usually a metacharacter in shells.
		1059	Supported operations are:
		1060
		1061	=over
		1062
		1063	=item B<WxH+X+Y>
		1064
		1065	sets scale and position. B<"W" / "H"> specify the horizontal/vertical
		1066	scale (percent), and B<"X" / "Y"> locate the image centre (percent). A
		1067	scale of 0 disables scaling.
		1068
		1069	=item B<op=tile>
		1070
		1071	enables tiling
		1072
		1073	=item B<op=keep-aspect>
		1074
		1075	maintain the image aspect ratio when scaling
		1076
		1077	=item B<op=root-align>
		1078
		1079	use the position of the terminal window relative to the root window as
		1080	the image offset, simulating a root window background
		1081
		1082	=back
		1083
		1084	The default scale and position setting is C<100x100+50+50>.
		1085	Alternatively, a predefined set of templates can be used to achieve
		1086	the most common setups:
		1087
		1088	=over
		1089
		1090	=item B<style=tiled>
		1091
		1092	the image is tiled with no scaling. Equivalent to 0x0+0+0:op=tile
		1093
		1094	=item B<style=aspect-stretched>
		1095
		1096	the image is scaled to fill the whole window maintaining the aspect
		1097	ratio and centered. Equivalent to 100x100+50+50:op=keep-aspect
		1098
		1099	=item B<style=stretched>
		1100
		1101	the image is scaled to fill the whole window. Equivalent to 100x100
		1102
		1103	=item B<style=centered>
		1104
		1105	the image is centered with no scaling. Equivalent to 0x0+50+50
		1106
		1107	=item B<style=root-tiled>
		1108
		1109	the image is tiled with no scaling and using 'root' positioning.
		1110	Equivalent to 0x0:op=tile:op=root-align
		1111
		1112	=back
		1113
		1114	If multiple templates are specified the last one wins. Note that a
		1115	template overrides all the scale, position and operations settings.
		1116
		1117	If used in conjunction with pseudo-transparency, the specified image
		1118	will be blended over the transparent background using alpha-blending.
		1119
		1120	=item B<-tr>\|B<+tr>
		1121
		1122	=item B<transparent:> I<boolean>
		1123
		1124	Turn on/off pseudo-transparency by using the root pixmap as background.
		1125
		1126	=item B<-tint> I<colour>
		1127
		1128	=item B<tintColor:> I<colour>
		1129
		1130	Tint the transparent background with the given colour. Note that a
		1131	black tint yields a completely black image while a white tint yields
		1132	the image unchanged.
		1133
		1134	=item B<-sh> I<number>
		1135
		1136	=item B<shading:> I<number>
		1137
		1138	Darken (0 .. 99) or lighten (101 .. 200) the transparent background.
		1139	A value of 100 means no shading.
		1140
		1141	=item B<-blr> I<HxV>
		1142
		1143	=item B<blurRadius:> I<HxV>
		1144
		1145	Apply gaussian blur with the specified radius to the transparent
		1146	background. If a single number is specified, the vertical and
		1147	horizontal radii are considered to be the same. Setting one of the
		1148	radii to 1 and the other to a large number creates interesting effects
		1149	on some backgrounds. The maximum radius value is 128. An horizontal or
		1150	vertical radius of 0 disables blurring.
		1151
		1152	=back
		1153
		1154	=head2 OSC sequences
		1155
		1156	This extension will react to the following OSC sequences. Note that
		1157	this extension will not be autoloaded when these are used currently,
		1158	so to make urxvt recognize them, you have to enable the C<background>
		1159	extension. One way to achieve that is to use the C<--background-expr ''>
		1160	command line argument or by specifying an empty C<URxvt.background.expr:>>
		1161	resource.
		1162
		1163	=over
		1164
		1165	=item B<< C<ESC ] 705 ; Pt ST> >> Change transparent background tint colour to B<< C<Pt> >>.
		1166
		1167	=item B<< C<ESC ] 20 ; Pt ST> >> Change/Query background image
		1168	parameters: the value of B<< C<Pt> >> can be one of the following
		1169	commands:
		1170
		1171	=over
		1172
		1173	=item B<< C<?> >>
		1174
		1175	display scale and position in the title
		1176
		1177	=item B<< C<;WxH+X+Y> >>
		1178
		1179	change scale and/or position
		1180
		1181	=item B<< C<FILE;WxH+X+Y> >>
		1182
		1183	change background image
		1184
		1185	=back
		1186
		1187	=cut
		1188
886	sub once(&) {	1189	sub keep(&) {
887	my $id = $_[0]+0;	1190	my $id = $_[0]+0;
888		1191
889	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];	1192	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
890		1193
891	unless ($frame->[FR_CACHE]) {	1194	unless ($frame->[FR_CACHE]) {
…		…
909	wantarray	1212	wantarray
910	? @{ $frame->[FR_CACHE] }	1213	? @{ $frame->[FR_CACHE] }
911	: $frame->[FR_CACHE][0]	1214	: $frame->[FR_CACHE][0]
912	}	1215	}
913		1216
914	sub once_again() {	1217	# sub keep_clear() {
915	delete $self->{frame_cache};	1218	# delete $self->{frame_cache};
916	}	1219	# }
917		1220
918	=back	1221	=back
919		1222
920	=cut	1223	=cut
921		1224
922	}	1225	}
923		1226
924	sub parse_expr {	1227	sub parse_expr {
		1228	my ($expr) = @_;
		1229
		1230	# an empty expression is valid and represents the default background
		1231	if ($expr !~ /\S/) {
		1232	$expr = sub {
		1233	undef
		1234	};
		1235	} else {
925	my $expr = eval	1236	$expr = eval
926	"sub {\n"	1237	"sub {\n"
927	. "package urxvt::bgdsl;\n"	1238	. "package urxvt::bgdsl;\n"
928	. "#line 0 'background expression'\n"	1239	. "#line 0 'background expression'\n"
929	. "$_[0]\n"	1240	. "$expr\n"
930	. "}";	1241	. "}";
931	die if $@;	1242	die if $@;
		1243	}
		1244
932	$expr	1245	$expr
933	}	1246	}
934		1247
935	# compiles a parsed expression	1248	# compiles a parsed expression
936	sub set_expr {	1249	sub set_expr {
937	my ($self, $expr) = @_;	1250	my ($self, $expr) = @_;
938		1251
939	$self->{root} = [];	1252	$self->{root} = []; # the outermost frame
940	$self->{expr} = $expr;	1253	$self->{expr} = $expr;
941	$self->recalculate;	1254	$self->recalculate;
942	}	1255	}
943		1256
944	# takes a hash of sensitivity indicators and installs watchers	1257	# takes a hash of sensitivity indicators and installs watchers
…		…
985	if ($again->{rootpmap}) {	1298	if ($again->{rootpmap}) {
986	$state->{rootpmap} = $self->on (rootpmap_change => $cb);	1299	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
987	} else {	1300	} else {
988	delete $state->{rootpmap};	1301	delete $state->{rootpmap};
989	}	1302	}
		1303
		1304	if ($again->{focus}) {
		1305	$state->{focus} = $self->on (focus_in => $cb, focus_out => $cb);
		1306	} else {
		1307	delete $state->{focus};
		1308	}
990	}	1309	}
991		1310
992	# evaluate the current bg expression	1311	# evaluate the current bg expression
993	sub recalculate {	1312	sub recalculate {
994	my ($arg_self) = @_;	1313	my ($arg_self) = @_;
…		…
1002	return;	1321	return;
1003	}	1322	}
1004		1323
1005	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1324	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
1006		1325
		1326	unless ($arg_self->has_render) {
		1327	warn "background extension needs RENDER extension 0.11 or higher, ignoring background-expr.\n";
		1328	return;
		1329	}
		1330
1007	# set environment to evaluate user expression	1331	# set environment to evaluate user expression
1008		1332
1009	local $self = $arg_self;	1333	local $self = $arg_self;
1010	local $HOME = $ENV{HOME};	1334	local $HOME = $ENV{HOME};
1011	local $frame = [];	1335	local $frame = $self->{root};
1012		1336
1013	($x, $y, $w, $h) = $self->background_geometry ($self->{border});	1337	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
		1338	$focus = $self->focus;
1014		1339
1015	# evaluate user expression	1340	# evaluate user expression
1016		1341
1017	my @img = eval { $self->{expr}->() };	1342	my @img = eval { $self->{expr}->() };
1018	die $@ if $@;	1343	die $@ if $@;
1019	die "background-expr did not return anything.\n" unless @img;	1344	die "background-expr did not return anything.\n" unless @img;
		1345
		1346	if ($img[0]) {
1020	die "background-expr: expected image(s), got something else.\n"	1347	die "background-expr: expected image(s), got something else.\n"
1021	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;	1348	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
1022		1349
1023	my $img = urxvt::bgdsl::merge @img;	1350	my $img = urxvt::bgdsl::merge @img;
1024		1351
1025	$frame->[FR_AGAIN]{size} = 1	1352	$frame->[urxvt::bgdsl::FR_AGAIN]{size} = 1
1026	if $img->repeat_mode != urxvt::RepeatNormal;	1353	if $img->repeat_mode != urxvt::RepeatNormal;
1027		1354
1028	# if the expression is sensitive to external events, prepare reevaluation then	1355	# if the expression is sensitive to external events, prepare reevaluation then
1029	$self->compile_frame ($frame, sub { $arg_self->recalculate });	1356	$self->compile_frame ($frame, sub { $arg_self->recalculate });
1030		1357
1031	# clear stuff we no longer need	1358	# clear stuff we no longer need
1032		1359
1033	# unless (%{ $frame->[FR_STATE] }) {	1360	# unless (%{ $frame->[FR_STATE] }) {
1034	# delete $self->{state};	1361	# delete $self->{state};
1035	# delete $self->{expr};	1362	# delete $self->{expr};
1036	# }	1363	# }
1037		1364
1038	# set background pixmap	1365	# set background pixmap
1039		1366
1040	$self->set_background ($img, $self->{border});	1367	$self->set_background ($img, $self->{border});
		1368	} else {
		1369	$self->clr_background;
		1370	}
		1371
1041	$self->scr_recolour (0);	1372	$self->scr_recolor (0);
1042	$self->want_refresh;	1373	$self->want_refresh;
1043	}	1374	}
1044		1375
		1376	sub old_bg_opts {
		1377	my ($self, $arg) = @_;
		1378
		1379	$arg or return;
		1380
		1381	my @str = split /;/, $arg;
		1382
		1383	return unless $str[0] or $self->{bg_opts}->{path};
		1384
		1385	my $bg_opts = $self->{bg_opts};
		1386
		1387	if ($str[0]) {
		1388	$bg_opts->{tile} = 0;
		1389	$bg_opts->{keep_aspect} = 0;
		1390	$bg_opts->{root_align} = 0;
		1391	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1392	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1393	$bg_opts->{path} = $str[0];
		1394	}
		1395
		1396	my @oplist = split /:/, $str[1];
		1397
		1398	for (@oplist) {
		1399	if (/style=tiled/i) {
		1400	$bg_opts->{tile} = 1;
		1401	$bg_opts->{keep_aspect} = 0;
		1402	$bg_opts->{root_align} = 0;
		1403	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1404	$bg_opts->{h_align} = $bg_opts->{v_align} = 0;
		1405	} elsif (/style=aspect-stretched/i) {
		1406	$bg_opts->{tile} = 0;
		1407	$bg_opts->{keep_aspect} = 1;
		1408	$bg_opts->{root_align} = 0;
		1409	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1410	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1411	} elsif (/style=stretched/i) {
		1412	$bg_opts->{tile} = 0;
		1413	$bg_opts->{keep_aspect} = 0;
		1414	$bg_opts->{root_align} = 0;
		1415	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1416	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1417	} elsif (/style=centered/i) {
		1418	$bg_opts->{tile} = 0;
		1419	$bg_opts->{keep_aspect} = 0;
		1420	$bg_opts->{root_align} = 0;
		1421	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1422	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1423	} elsif (/style=root-tiled/i) {
		1424	$bg_opts->{tile} = 1;
		1425	$bg_opts->{keep_aspect} = 0;
		1426	$bg_opts->{root_align} = 1;
		1427	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1428	$bg_opts->{h_align} = $bg_opts->{v_align} = 0;
		1429	} elsif (/op=tile/i) {
		1430	$bg_opts->{tile} = 1;
		1431	} elsif (/op=keep-aspect/i) {
		1432	$bg_opts->{keep_aspect} = 1;
		1433	} elsif (/op=root-align/i) {
		1434	$bg_opts->{root_align} = 1;
		1435	} elsif (/^ =? ([0-9]+)? (?:[xX] ([0-9]+))? ([+-][0-9]+)? ([+-][0-9]+)? $/x) {
		1436	my ($w, $h, $x, $y) = ($1, $2, $3, $4);
		1437
		1438	if ($str[0]) {
		1439	$w = $h unless defined $w;
		1440	$h = $w unless defined $h;
		1441	$y = $x unless defined $y;
		1442	}
		1443
		1444	$bg_opts->{h_scale} = $w if defined $w;
		1445	$bg_opts->{v_scale} = $h if defined $h;
		1446	$bg_opts->{h_align} = $x if defined $x;
		1447	$bg_opts->{v_align} = $y if defined $y;
		1448	}
		1449	}
		1450	}
		1451
		1452	# helper function, quote string as perl without allowing
		1453	# any code execution or other shenanigans. does not
		1454	# support binary NULs in string.
		1455	sub q0 {
		1456	(my $str = shift) =~ s/\x00//g; # make sure there really aren't any embedded NULs
		1457	"q\x00$str\x00"
		1458	}
		1459
		1460	sub old_bg_expr {
		1461	my ($self) = @_;
		1462
		1463	my $expr;
		1464
		1465	my $bg_opts = $self->{bg_opts};
		1466
		1467	if ($bg_opts->{root} =~ /^\s(?:true\|yes\|on\|1)\s$/i) {
		1468	$expr .= "tile (";
		1469
		1470	my $shade = $bg_opts->{shade};
		1471
		1472	if ($shade) {
		1473	$shade = List::Util::min $shade, 200;
		1474	$shade = List::Util::max $shade, -100;
		1475	$shade = 200 - (100 + $shade) if $shade < 0;
		1476
		1477	$shade = $shade * 0.01 - 1;
		1478	$expr .= "shade $shade, ";
		1479	}
		1480
		1481	my $tint = $bg_opts->{tint};
		1482
		1483	if ($tint) {
		1484	$tint = q0 $tint;
		1485	$expr .= "tint $tint,";
		1486	}
		1487
		1488	my $blur = $bg_opts->{blur};
		1489
		1490	if ($blur and $blur =~ /^ =? ([0-9]+)? (?:[xX] ([0-9]+))? $/x) {
		1491	my $hr = defined $1 ? $1 : 1;
		1492	my $vr = defined $2 ? $2 : $hr;
		1493
		1494	if ($hr != 0 and $vr != 0) {
		1495	$expr .= "blur $hr, $vr, ";
		1496	}
		1497	}
		1498
		1499	$expr .= "rootalign root)";
		1500	}
		1501
		1502	if ($bg_opts->{path}) {
		1503	my $file_expr;
		1504	my $h_scale = $bg_opts->{h_scale} * 0.01;
		1505	my $v_scale = $bg_opts->{v_scale} * 0.01;
		1506	my $h_align = $bg_opts->{h_align} * 0.01;
		1507	my $v_align = $bg_opts->{v_align} * 0.01;
		1508
		1509	if (!$bg_opts->{tile}) {
		1510	$file_expr .= "pad (";
		1511	} else {
		1512	$file_expr .= "tile (";
		1513	}
		1514
		1515	if ($bg_opts->{root_align}) {
		1516	$file_expr .= "rootalign ";
		1517	} else {
		1518	$file_expr .= "align $h_align, $v_align, ";
		1519	}
		1520
		1521	if ($h_scale != 0 and $v_scale != 0) {
		1522	my $op = $bg_opts->{keep_aspect} ? "fit" : "resize";
		1523	$file_expr .= "$op TW * $h_scale, TH * $v_scale, ";
		1524	}
		1525
		1526	my $path = q0 $bg_opts->{path};
		1527
		1528	$file_expr .= "keep { load $path })";
		1529
		1530	if ($expr) {
		1531	$expr .= ", tint (\"[50]white\", $file_expr)";
		1532	} else {
		1533	$expr = $file_expr;
		1534	}
		1535	}
		1536
		1537	$expr
		1538	}
		1539
		1540	sub find_resource {
		1541	my ($self, $res, $opt) = @_;
		1542
		1543	my $v = $self->x_resource ($opt);
		1544	$v = $self->x_resource ($res) unless defined $v;
		1545
		1546	$v
		1547	}
		1548
		1549	sub parse_bgopts {
		1550	my ($self) = @_;
		1551
		1552	my $expr = $self->x_resource ("%.expr");
		1553
		1554	if (!$expr) {
		1555	$self->{bg_opts} = { h_scale => 100, v_scale => 100,
		1556	h_align => 50, v_align => 50 };
		1557
		1558	$self->{bg_opts}{shade} = $self->find_resource ("shading", "sh");
		1559	$self->{bg_opts}{tint} = $self->find_resource ("tintColor", "tint");
		1560	$self->{bg_opts}{blur} = $self->find_resource ("blurRadius", "blr");
		1561	$self->{bg_opts}{root} = $self->find_resource ("transparent", "tr");
		1562
		1563	$self->old_bg_opts ($self->find_resource ("backgroundPixmap", "pixmap"));
		1564	$expr = $self->old_bg_expr;
		1565	}
		1566
		1567	$self->set_expr (parse_expr $expr);
		1568	$self->{border} = $self->x_resource_boolean ("%.border");
		1569
		1570	$MIN_INTERVAL = $self->x_resource ("%.interval");
		1571	}
		1572
1045	sub on_start {	1573	sub on_start {
1046	my ($self) = @_;	1574	my ($self) = @_;
1047		1575
1048	my $expr = $self->x_resource ("%.expr")	1576	$self->parse_bgopts;
1049	or return;
1050
1051	$self->has_render
1052	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
1053
1054	$self->set_expr (parse_expr $expr);
1055	$self->{border} = $self->x_resource_boolean ("%.border");
1056
1057	$MIN_INTERVAL = $self->x_resource ("%.interval");
1058		1577
1059	()	1578	()
1060	}	1579	}
1061		1580
		1581	sub on_osc_seq {
		1582	my ($self, $op, $arg) = @_;
		1583
		1584	$op eq "20" or $op eq "706"
		1585	or return;
		1586
		1587	$self->{bg_opts}
		1588	or $self->parse_bgopts;
		1589
		1590	if ($op eq "20") {
		1591	if ($arg eq "?") {
		1592	my $h_scale = $self->{bg_opts}{h_scale};
		1593	my $v_scale = $self->{bg_opts}{v_scale};
		1594	my $h_align = $self->{bg_opts}{h_align};
		1595	my $v_align = $self->{bg_opts}{v_align};
		1596	$self->cmd_parse ("\033]2;[${h_scale}x${v_scale}+${h_align}+${v_align}]\007");
		1597	} else {
		1598	$self->old_bg_opts ($arg);
		1599	my $expr = $self->old_bg_expr;
		1600	$self->set_expr (parse_expr $expr) if $expr;
		1601	}
		1602	} elsif ($op eq "705") {
		1603	$self->{bg_opts}{tint} = $arg;
		1604	my $expr = $self->old_bg_expr;
		1605	$self->set_expr (parse_expr $expr) if $expr;
		1606	}
		1607
		1608	1
		1609	}
		1610

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.66 by root, Thu Jun 28 15:19:15 2012 UTC vs. Revision 1.103 by root, Fri Nov 26 18:49:48 2021 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.66 by root, Thu Jun 28 15:19:15 2012 UTC vs.
Revision 1.103 by root, Fri Nov 26 18:49:48 2021 UTC